What’s High Availability
High availability is a critical success factor for any given enterprise application. Today we’ll go through how to design and deploy an application with high availability. First things first. Let’s see what’s high availability.
High availability is a characteristic of a system, which describes the duration (length of time) for which the system is operational. – Wikipedia
In simple words high availability can be defined as running a system 24*7 without a downtime even if there are hardware and software failures. In other way a fault tolerance application. This helps ensure uninterrupted use of the application for it’s intended users. If you need more information you can read this article. Also you might be thinking when is the right time to introduce high availability in your application? The answer is here.
Following is an architecture that supports high availability. It’s the minimal requirement to implement high availability in your application(Note that in the database cluster you can have master-slave instead of master-master depending on your requirement).
Hello there everyone! What’s open data, Why open data? What’s CKAN? Today we are gonna go through all that. Yeah ALL that. You know open data is one of the most used buzzword in 2013 and I hope it will remain as it’s in 2014 too. Okay enough pep talk. Let’s divine into it. I know I know your 1st question will be
What’s open data?
“Open data is the idea that certain data should be freely available to everyone to use and republish as they wish, without restrictions from copyright, patents or other mechanisms of control.” – wikipedia
So It’s nothing big. It is what it’s name implies. Data that anyone can use. Data that anyone modify and republish. Best part it is you can do anything you want with the data without any restrictions. Yeah anything. You know what? I went through the open data hand book as well. Guess what I found.
“Open data is data that can be freely used, reused and redistributed by anyone – subject only, at most, to the requirement to attribute and sharealike.” – opendatahandbook
There you have it. Another definition but don’t those words say the same thing? Yeah It’s the same. Free data, Free world, Use it however you want. (happy-face). Okay shall we move on the WHY part now please?
Let’s take a look at what’s regular expression and it’s use in the development environment. 1st of all regular expression is a small piece of code which looks for pattern(s). In web development environment Regex are used in the .htaccess file most frequently. Regexs are supposed to make developer’s life easier but most of the time it’s the other way around. Let’s stop the chit-chat and go through some technical aspects of Regexs.